Index: /trunk/src/VBox/VMM/VMMR3/PDMDevice.cpp
===================================================================
--- /trunk/src/VBox/VMM/VMMR3/PDMDevice.cpp	(revision 82456)
+++ /trunk/src/VBox/VMM/VMMR3/PDMDevice.cpp	(revision 82457)
@@ -804,4 +804,7 @@
                           ("%#x (szName=%s)\n", pReg->cMaxMsixVectors, pReg->szName),
                           VERR_PDM_INVALID_DEVICE_REGISTRATION);
+    AssertLogRelMsgReturn(pReg->fFlags & PDM_DEVREG_FLAGS_NEW_STYLE /* the flag is required now */,
+                          ("PDM_DEVREG_FLAGS_NEW_STYLE not set for szName=%s!\n", pReg->szName),
+                          VERR_PDM_INVALID_DEVICE_REGISTRATION);
 
     /*